Javascript value parameter has no effect

I'm having trouble prepopulating the textarea using the Javascript method; my code looks like this:

<pre>
<script type="text/javascript" src="/fckeditor/fckeditor.js"></script>
<form>
<script type="text/javascript">
var oFCKeditor = new FCKeditor( 'fieldname' ) ;
oFCKeditor.Create() ;
oFCKeditor.Width = "100%" ;
oFCKeditor.Value = "[this is the value]" ;
</script>
</form>
</pre>

The textarea shows up blank. Any advice?